Sunan an-Nasa'i #3616 · The Book of Wills

Sunan an-Nasa'iIt was narrated from Ibn 'Umar that the Messenger of Allah said
Sunan an-Nasa'i · Book 30 · The Book of Wills
Sunan an-Nasa'i · كتاب 30 · كتاب الوصايا
"It is not befitting for a Muslim who has anything concerning which a will should be made, to abide for two nights without having a written will with him
أَخْبَرَنَا مُحَمَّدُ بْنُ سَلَمَةَ، قَالَ حَدَّثَنَا ابْنُ الْقَاسِمِ، عَنْ مَالِكٍ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏
"‏ مَا حَقُّ امْرِئٍ مُسْلِمٍ لَهُ شَىْءٌ يُوصَى فِيهِ يَبِيتُ لَيْلَتَيْنِ إِلاَّ وَوَصِيَّتُهُ مَكْتُوبَةٌ عِنْدَهُ ‏"‏‏.‏
Reference : Sunan an-Nasa'i 3616In-book reference : Book 30, Hadith 6